The best thing would be to simply check that $SRVCH conforms to what you expect, that is, a sequence of only digits, before doing the numerical checks:

if(   ($SRVCH =~ /\D/) # a non-digit
   || ($SRVCH > 22)    # or greater 22
   ||($SRVCH < 1)      # or smaller than 1
   ||($SRVCH =~ /(\s+)/) # or empty string (but see above)
   ||($SRVCH =~ /[a-zA-Z]/) # or a to z
){ ...

[download]

Also, there is no need to shell out to sleep, because Perl has sleep as a built-in function. See also Time::HiRes if you need sub-second sleep.

In reply to Re: Suppressing Warning/Error messages by Corion
in thread Suppressing Warning/Error messages by intoperl

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